﻿/**
 * Copyright (C) 2013 original author and authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using NGuice.Inject.Spi;
using System.Reflection;
using NGuice.Inject.Internal.Util;

namespace NGuice.Inject.Internal
{
    internal class DelegatingInvocationHandler<T> : InvocationHandler
    {
        private T delegatee;

        public T Delegatee
        {
            get { return delegatee; }
            set { delegatee = value; }
        }

        public object Invoke(object proxy, MethodInfo method, object[] args)
        {
            if (delegatee == null)
            {
                throw new IllegalStateException("This is a proxy used to support"
                    + " circular references involving constructors. The object we're"
                    + " proxying is not constructed yet. Please wait until after"
                    + " injection has completed to use this object.");
            }

            try
            {
                return method.Invoke(delegatee, args);
            }
            catch (TargetInvocationException e)
            {
                throw e.InnerException;
            }
            catch (Exception e)
            {
                throw new ApplicationException("invoke method exception", e);
            }
        }
    }
}
